Rebutting Fixed Earth Argument: A Response

[Gabe911]

the other day i read this argument for the idea that the Earth doesn't rotate upon its axis. the argument goes like this:

“Two birds fly from a branch of a tree with equal speed to that of the earth’s rotation which is 1036 mph and one flies to the east and the other to the west. The one flying to the west will reach a distance of 2072 miles because as much as it went to the west, this branch went to the east due to the earth’s rotation. And the one going to the east will not move a hair’s length from the branch because as he is flying with the same speed the branch of the tree too, is going along with it. But we practically observe that both of them have equal speed going opposite to each other, and go to the same distance. If their speed of flying is less than that of the earth, for example 1035 mph, then the west-bound one will reach a distance of 2071 miles to the west. And its opponent, the east bound having toiled for an hour and having traversed 1035 miles will find itself only a mile away from the branch of that tree and that too, to its west. Isn’t it awkward that he just flew to the east direction and found himself to the west of the place? All this is absurd, false and contrary to observation.”

how would one respond to this argument?

 

[1MileCrash]

Simply put, the bird is traveling 1036 MPH relevant to the rotating reference frame of earth, not relative to a reference "overlooking" Earth's orbit.

The one that flew west will still only reach 1036 miles relative to our rotating earth. He doesn't stop rotating with the Earth when he starts to fly.

The one who flew east will also reach 1036 miles relative to rotating earth. He is still rotating with the earth.

The question switches reference frames in the middle of the problem. It starts with a bird that is stationary relative to earth, but it's already moving at 1036 MPH with Earth from the second frame introduced, one "overlooking" Earth's rotation. The speed of Earth's rotation combined with the bird's speed only add to 2072 MPH from a frame of reference "overlooking" Earth's rotation. From the bird's reference frame the Earth is not rotating, from the Earth's frame the bird is initially stationary, and when it starts flying 1036 MPH, it's flying 1036 MPH, not 2072 MPH.


If you do not switch reference frames, you get the correct results, which is that the bird travels 1036 miles in either direction regardless of Earth rotation.

 

[Danger]

Such measurements are usually taken in reference to the Earth, though, so each bird flies at only its "airspeed". Really... breaking Mach would blow the feathers off of any bird that I'm familiar with.

 

[Drakkith]

The air is moving with the Earth's rotation, so the birds fly in relation to already moving air.

 

[Curl]

how would one respond to this argument?

to be honest and tell you how *I* would respond to this argument, I would say something like:

"wow, you're dumb dude just be quiet"

That's what I would say. You asked...